David, Got a couple of sites for you dealing with impedance calcs, crosstalk cals, noise issues, etc. 1) check out WWW.AUTOMATA.COM (engineering tools section) 2) try WWW.ULTRACAD.COM, look for UltraCLC and/or UltraCT Great tools, FREE! There are more tools available on the web, but none I've found are quite as good (versatile). :) Good luck, Mitch Morey Sr PCB Designer ComStream Corp San Diego CA 92121 Email: [log in to unmask] Check out: www.comstream.com >>> <[log in to unmask]> 02/04/98 10:52am >>> I noticed your posting on the web and am curious if you ever found a satisfactory solution during your search. I likewise am interested in similar software and don't desire to re-invent the wheel. If you found a good package, especially if it's free, please clue me in to the source. Thank you for your time, David Nix [log in to unmask] (work) or [log in to unmask] (personal) ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################ ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################